Method for service compatibility-type transmitting in digital broadcast

ABSTRACT

A method for transmitting and receiving service-compatible 3D stereo digital TV signal broadcast supports both MPEG-2 TS-level and ES-level multiplexing when left and right compressed bitstreams are multiplexed and when service compatibility is enabled.

TECHNICAL FIELD

The present invention relates to a service-compatible mode of a 3Dstereoscopic digital broadcast in a MPEG-2 Transport Stream (TS) formatfor broadcasting used for digital TV transmission and reception.

BACKGROUND ART

In Korea, a standard of Advanced Television Systems Committee (ATSC) inNorth America, which is an 8-VSB system, was adopted as a terrestrialdigital broadcast system in November 1997. Subsequently, related coretechnology has been developed, field tests have been carried out, andtest broadcasting has been performed. Since 2001, existing analogbroadcasting and digital broadcasting have been simultaneouslyperformed. In 2012, however, switch to digital broadcasting will havebeen completed.

ATSC is an America committee developing a digital televisionbroadcasting standard or a standard of the committee. The standard ofATSC has been used as a national standard in America, Canada, Mexico,and Korea. In addition, the standard of ATSC will be adopted in othercountries, including several nations in South America. In addition toATSC, DVB, which has been developed in Europe, and ISDB of Japan areused as the standard of the digital broadcasting.

According to an ATSC digital broadcasting standard that is capable oftransmitting high-quality video, audio, and auxiliary data, data aretransmitted at a data transmission rate of 19.39 Mbps for a terrestrialbroadcast channel of 6 MHz and data are transmitted at a datatransmission rate of 38 Mbps for a cable TV channel. An ISO/IEC 13818-2MPEG-2 video standard is used as a video compression technology used inthe ATSC system. MPEG-2 MP@HL, i.e. Main Profile and High Level, is usedas a compression format. Video formats and limitations related theretoare defined.

Hereinafter, a description will be given of transmission modes which maybe used when a new broadcast, such as a 3D stereoscopic broadcast, ultrahigh definition (UHD) TV broadcast, or multi-view broadcast, is providedwhile maintaining compatibility with existing broadcast channels in aMPEG-2 TS format for broadcasting used for digital TV transmission andreception. Hereinafter, the 3D stereoscopic broadcast, UHD TV broadcast,and multi-view broadcast will be referred to as a composite imagebroadcast. Transmission modes which may be used in the MPEG-2 TS formatare divided into a frame-compatible mode and a service-compatible mode.In a case in which two transmission modes are used in a digitalbroadcast, it is necessary for a receiving end to recognize atransmission mode used by a transmission end.

DISCLOSURE Technical Problem

An object of the present invention is to provide a method oftransmitting detailed information of a 3D broadcast.

Another object of the present invention is to provide a method oftransmitting detailed information of a service-compatible mode, which isone transmission mode of a 3D broadcast.

A further object of the present invention is to provide a method oftransmitting detailed information supporting both TS-level multiplexingand ES-level multiplexing when multiplexing left and right compressionbitstreams in a service-compatible mode.

Technical Solution

In accordance with an aspect of the present invention, the above objectsmay be accomplished by the provision of a method of transmittingdetailed information supporting both TS-level multiplexing and ES-levelmultiplexing when multiplexing left and right compression bitstreams ina service-compatible mode.

Advantageous Effects

The present invention provides a method of transmitting detailedinformation supporting both TS-level multiplexing and ES-levelmultiplexing when multiplexing left and right compression bitstreams ina service-compatible mode during 3D broadcasting.

When 3D broadcasting is performed using the method of transmittingdetailed information according to the present invention, it is possibleto realize efficient broadcast transmission and reception based onvarious service-compatible mode environments, such as TS-levelmultiplexing and ES-level multiplexing, while maintaining compatibilitywith an existing broadcast using an existing broadcasting system.

DESCRIPTION OF DRAWINGS

FIG. 1 is a view showing a frame-compatible mode according to anembodiment of the present invention;

FIG. 2 is a view showing a service-compatible mode according to anembodiment of the present invention;

FIG. 3 is a view showing TS-level multiplexing and ES-level multiplexingin the service-compatible mode according to the embodiment of thepresent invention;

FIG. 4 is a view showing the structure of a program map table (PMT)syntax according to an embodiment of the present invention;

FIG. 5 is a view showingservice_compatible_stereoscopic_video_descriptor according to anembodiment of the present invention;

FIG. 6 is a view showing stereoscopic_stream_descriptor according to anembodiment of the present invention;

FIG. 7 is a view showingMPEG2_video_(—)3d_frame_frame_packing_arrangement_descriptor accordingto an embodiment of the present invention;

FIG. 8 is a flowchart showing a multiplexing process in theservice-compatible mode according to the embodiment of the presentinvention;

FIG. 9 is a view showing a process of de-assembling bitstreams of leftand right images when using an MVC bitstream assembling method inES-level bitstream multiplexing according to an embodiment of thepresent invention; and

FIG. 10 is a view showing MVC bitstream assembling and de-assembling.

DESCRIPTION OF THE REFERENCE NUMERALS

FIG. 2: Frame-compatible mode FIG. 3: Service-compatible mode

BEST MODE

The above and other aspects of the present invention will be moreclearly understood from the following detailed description of preferredembodiments taken in conjunction with the accompanying drawings.Hereinafter, the detailed description of the preferred embodiments ofthe present invention will be given to enable those skilled in the artto easily understand and reproduce the invention.

First, types of digital broadcasts will be described. Generally, digitalbroadcasts are classified into a 3-D stereoscopic broadcast, an UltraHigh Definition (UHD) TV broadcast, and a Multi-view broadcast.

An HD broadcast transmits one image. However, the 3-D stereoscopicbroadcast transmits two images, the UHD broadcast transmits four images(in case of 4k), and the multi-view broadcast transmits two or moreimages.

The 3-D stereoscopic broadcast is a method of assigning a PacketIdentifier (PID) for MPEG2-TS to left and right images and performingmultiplexing transmission to transmit a stereo type three-dimensionalstereoscopic image. A UHD image generally has a number of horizontal andvertical pixels ranging from 4000 level (4k·3840×2160) to 8000 level(8k·7680×4320). Since image resolution depends upon the number ofpixels, the 4k-based UHD image is four times clearer than an HD image(2k·1920×1080). The 8k-based UHD image is sixteen times clearer than theHD image. The HD image has a refresh rate, i.e. the number of frames persecond, of 30 Hz. In the UHD image, on the other hand, 60 images aretransmitted per second, thereby realizing much more natural and dynamicimages.

In the multi-view broadcast, two images, such as top and bottom imagesor left and right images, having angles different according to a users'viewing angle are combined such that the users view a 3-D stereoscopicimage. In a case in which a television is provided with a multi-viewdisplay device, a left person views a left face of a performer and aright person views a right face of the performer when the performerappears on a screen. That is, the multi-view broadcast is an advancedtype of the 3-D stereoscopic broadcast.

The present invention proposes a transmission and reception standard fortransmission modes suitable to perform a new broadcast while maintainingcompatibility with an existing broadcast channel when using any oneselected from among the 3-D stereoscopic broadcast, the UHD TVbroadcast, and the multi-view broadcast.

Hereinafter, a frame-compatible mode, which is one of the transmissionmodes, will be described first and then a service-compatible mode, whichis another of the transmission modes, will be described.

FIG. 1A shows a frame-compatible mode and FIG. 1B shows examples ofmethods of synthesizing images to configure the frame-compatible mode.FIGS. 1A and 1B show an example of a 3-D stereoscopic broadcast.However, the present invention may be extended to a UHD TV broadcast anda multi-view broadcast in a similar manner. Hereinafter, theframe-compatible mode will be described in detail with reference toFIGS. 1A and 1B.

Referring to FIG. 1B, a frame containing combined left and right imagesis transmitted through a transmission band in the frame-compatible mode.Consequently, a transmission and reception form identical to a form usedin a conventional HD broadcast may be maintained. However, the broadcastin the frame-compatible mode is different from the conventional HDbroadcast in that the conventional HD broadcast transmit a video to theentire region but the broadcast in the frame-compatible mode transmitsan image synthesized based on the number of images. That is, as shown inFIG. 1B, a left image and a right image may be synthesized into a frameusing various methods. As shown in FIG. 2B (a), a frame may be dividedinto two halves and then synthesized. As shown in FIG. 1B(b), a framemay be divided in pixel steps and then synthesized. Alternatively, asshown in FIG. 1B(c), left and right images may be sequentiallytransmitted while a frame is maintained. In FIGS. 1B(a) and 1B(b), aspecific number of images are synthesized into a frame; therefore, aprocess of reducing each image is necessary. In FIG. 1B(c), a frame-rateis increased; therefore, it is necessary to increase a bandwidth or toadjust a video compression bitrate. There are various methods ofsynthesizing images. In the 3-D stereoscopic image as shown in FIG. 1B,the left image and the right image may be changed or the images may bemixed in diagonal pixel steps.

In the 3-D stereoscopic broadcast, for example, both the left image andthe right image are transmitted through one transmission band.Consequently, the 3-D stereoscopic broadcast has an half lower imageresolution than in a case in which an image frame is transmitted withthe result that image quality is deteriorated (FIGS. 1B(a) and 1B(b)).Otherwise, much more data must be transmitted in the same bandwidth. Tothis end, it is necessary to increase a compression rate with the resultthat image quality is deteriorated or a frame rate is lowered (FIG.1B(c)).

FIG. 2 shows a service-compatible mode. Hereinafter, theservice-compatible mode will be described in detail with reference toFIG. 2. FIG. 2 shows an example of a 3-D stereoscopic broadcast.However, the present invention may be extended to a UHD TV broadcast anda multi-view broadcast in a similar manner.

Referring to FIG. 2, a left image frame and a right image frame areindividually compressed and transmitted through a transmission bandwithout image synthesis in the service-compatible mode. That is, asshown in FIG. 2, the left image frame and the right image frame arecompressed using corresponding compression methods and the compressedleft image frame and right image frame are transmitted through onetransmission band. In order to transmit two or more compressed imagesthrough a limited transmission band, one of the image is compressed soas to be compatible with an existing HD broadcast, whereas the otherimage is transmitted while being coded using a compression method havinga higher compression rate. Alternatively, one of the left and rightimages is transmitted in a high resolution state and the other image istransmitted in a low resolution state. As an example, the left image istransmitted while being coded using MPEG-2 Main profile and the rightimage is transmitted while being coded using MPEG-4 AVC/H.264 Highprofile. In a case in which low resolution is used, an image stream ofthe left image is transmitted at a resolution of 1080i@60 Hz using theabove coding method and an image stream of the right image istransmitted at a resolution of 720p@60 Hz using the above coding method.In addition, the right image is sub-sampled in the vertical orhorizontal direction while the left image is not changed and a receivingunit restores the sampled right image so as to correspond to theresolution of the left image to form one stereoscopic image.

When a new broadcast is performed while maintaining compatibility withan existing broadcast channel in the digital broadcast as describedabove, a transmission mode of a composite broadcast is divided into aframe-compatible mode and a service-compatible mode. An transmission endtransmits a compressed image to a receiving end using one of the twotransmission modes. The receiving end must recognize the transmissionmode used by the transmission end to decode the received compressedimage. An existing broadcast receiving system that is not capable ofprocessing the composite images disregards a secondary view of thereceived composite images and reproduces only a primary view of thereceived composite images. Consequently, it is possible to selectivelyreceive the composite broadcast while maintaining compatibility with theexisting broadcast channel.

FIG. 3 shows left and right image multiplexing used in theservice-compatible mode according to the embodiment of the presentinvention. Hereinafter, the left and right image multiplexing used inthe service-compatible mode according to the embodiment of the presentinvention will be described with reference to FIG. 3.

Referring to FIG. 3, the multiplexing used in the service-compatiblemode is divided into TS-level multiplexing and ES-level multiplexing.

The TS-level multiplexing is a method of assigning different PIDs toPacketized Elementary Streams (PES) acquired by packetizing ElementaryStreams (ES) of the left and right images. It is necessary to specify aPID of a reference image. That is, as shown in FIG. 3, different PIDsare assigned to the left image and the right image.

On the other hand, the ES-level multiplexing is a method of combiningcompressed bitstreams (ES) of the left and right images into oneElementary Stream (ES) and transmitting the Elementary Stream using aPID. In the ES-level multiplexing, therefore, it is necessary to providea method of dividing one Elementary Stream (ES) into compressedbitstreams of the left and right images. As an example, Byte Offset maybe used. That is, as shown in FIG. 3, one PID is assigned to the leftimage and the right image and offset for division into the left imageand the right image is used. That is, the ES-level multiplexing is amethod of assembling compressed bitstreams of the left and right imagesinto one compressed bitstream (ES), assigning one PID to a PES acquiredby packetizing Elementary Stream (ES), and transmitting the PES. It isnecessary for the receiving unit to de-assemble or bitstream extract thePES into compressed bitstreams of the left and right images. As anexample, MVC bitstream assembling is used. Alternatively, it isnecessary to specify an additional syntax, such as Byte Offset, forde-assembling into two images. FIGS. 9 and 10 show a de-assemblingprocess when using MVC bitstream assembling and assembling andde-assembling.

In an embodiment of the present invention, a receiving system that iscapable of processing a 3D image receives identification information torecognize the reception of a 3D image while the identificationinformation is contained in system information. Program SpecificInformation/Program and System Information Protocol (PSI/PSIP) isapplied as system information; however, the present invention is notlimited thereto. That is, any protocol transmitting system informationas a table format may be applied to the present invention irrespectiveof the term thereof.

PSI is a system standard of MPEG-2 defined to classify channels andprograms. PSIP is a standard of Advanced Television Systems Committee(ATSC) that is capable of classifying channels and programs.

In an embodiment, PSI may include a Program Association Table (PAT),Conditional Access Table (CAT), Program Map Table (PMT), and NetworkInformation Table (NIT).

PAT is specific information transmitted by a packet having a PID of 0.PID information of PMT and PID information of NIT are transmitted foreach program by using the PAT. CAT transmits information regarding acharged broadcast system used by the transmission side. PMT transmitsPID information of a transport stream packet to transmit individualbitstreams of video and audio constituting a program, programidentification number and PID information to transmit PCR. NIT transmitsinformation of a real transmission network. For example, a PAT tablehaving a PID of 0 is parsed to find program number and PID of PMT. PMTobtained from PAT is parsed to know a correlation between componentsconstituting the program.

FIG. 4 is a view showing the structure of a program map table (PMT)syntax according to an embodiment of the present invention. Hereinafter,the structure of a program map table (PMT) syntax according to anembodiment of the present invention will be described in detail withreference to FIG. 4.

Referring to FIG. 4, a table_id field is a table identifier. Anidentifier to identify PMT may be set. A section_syntax_indicator fieldis an indicator to define a section form of PMT. A section_length fieldindicates the section length of PMT.

A program_number field indicates program number as informationcoinciding with PAT. A version_number field indicates version number ofPMT. A current_next_indicator field is an indicator to indicate whetherthe current table section is applicable.

A section_number field indicates section number of the current PMTsection when PMT is transmitted while being divided into one or moresections. A last_section_number field indicates last section number ofPMT. A PCR_PID field indicates PID of a packet that transmits programclock reference (PCR) of the current program.

A program_info_length field indicates length information of descriptorsfollowing the program_info_length field in bytes. That is, theprogram_info_length field indicates length of descriptors included in afirst loop. A stream_type field indicates coding information and type ofan elementary stream included in a packet having a PID value indicatedby the following elementary_PID field. A elementary_PID field indicatesan identifier of the elementary stream, i.e. a PID value of a packetincluding the elementary stream. An ES_Info_length field indicateslength information of descriptors following the ES_Info_length field inbytes. That is, the ES_Info_length field indicates length of descriptorsincluded in a second loop.

In addition, referring to FIG. 4, a descriptor related to synthesisinformation regarding left and right images for specific program number,i.e. a descriptor related to a transmission mode, is present in adescriptor following a program_info_length syntax. In addition, adescriptor related to individual ESs of left and right images is presentin a descriptor following an ES_info_length syntax. Referring to FIG. 4,the descriptor related to synthesis information regarding left and rightimages is defined as service_compatible_stereoscopic_video_descriptor(). Information related to frame packing arrangement describesMPEG2_video_(—)3d-frame_packing_arrangement_descriptor( ) defined in theframe-compatible mode. However,MPEG2_video_(—)3d_frame_frame_packing_arrangement_descriptor( ) may notbe located at the current position but at a descriptor underES_info_length. This is because one video PID is provided in theframe-compatible mode; therefore, the PID is present together with thedescriptor. The descriptor related to the individual ESs of left andright images is defined as stereoscopic_stream_descriptor( ) Referringto FIG. 4, however, these descriptors are directly expressed in thesyntax to indicate the positions of the descriptors. In fact, however,the descriptors are selectively included like conventional descriptors.

Referring to FIG. 4, the descriptor related to synthesis informationregarding left and right images for specific program number is firstconfigured and then the descriptor related to individual ESs of left andright images is configured; however, the present invention is notlimited thereto. That is, as previously described, the positions of thedescriptors of FIG. 4 may be variable as the position ofMPEG2_video_(—)3d_frame_frame_packing_arrangement_descriptor( ) isvariable.

Table 1 below indicates stream type shown in FIG. 4.

TABLE 1 Value Description Ox00 ITU-T/ISO/IEC Reserved Ox01 ISO/IEC11172-2 Video Ox02 ITU-T Rec. H.262/ISO/IEC 13818-2 Video or ISO/IEC11172-2 constrained parameter video stream Ox03 ISO/IEC 11172-3 VideoOx04 ISO/IEC 13818-3 Video . . . . . . Ox0A ISO/IEC 13818-8 type A . . .. . . Ox22 ITU-T Rec. h.262/ISO/IEC 13818-2 Video with stereoscopiccount coded using frame packing arrangement . . . . . . Ox80-OxFF UserPrivate

FIG. 5 shows service_compatible_stereoscopic_video_descriptor accordingto an embodiment of the present invention. Hereinafter,service_compatible_stereoscopic_video_descriptor according to anembodiment of the present invention will be described in detail withreference to FIG. 5.

As previously described,service_compatible_stereoscopic_video_descriptor is a descriptor relatedto synthesis information regarding left and right images and includesresolution of the left and right images, limitation of secondary viewwatching, whether a GOP structure is arranged, and whether ES-levelmultiplexing is used. Particularly, FIG. 5 a shows an example in whichPID is not used and FIG. 5 b shows an example in which PID is used.

First, an example in which PID is not used will be described withreference to FIG. 5 a.

If Resolution_Conversion_flag is 1, it means thatPrimary_Conversion_Type and Secondary_Conversion_Type syntaxes arepresent. If Resolution_Conversion_flag is 0, it means that left andright images have the same resolution.

Primary_Conversion_Type indicates division of a primary view based on anoriginal image, which is indicated in Table 2. However, values and itemsof Table 2 may be changed, reduced, or extended as needed.

TABLE 2 Value 0 1 2 3 Meanings No change Horizontal Vertical Horizontalin size two two and division division vertical two division

Secondary_Conversion_Type indicates division of a secondary view basedon an original image, which is indicated in Table 2.

If Allowance_of_Secondary_View_Presentation_flag is 1, it means that thesecondary view may be independently output to a screen as a 2D service.The primary view is allowed to be always independently output to ascreen as a 2D service, whereas the secondary view may be prohibited orallowed to be output as 2D according to applications.

If Alignment_of_GOP_Structure_flag is 1, it means that GOP structures ofthe left and right images coincide with each other. In a case in whichthe GOP structures of the left and right images do not coincide witheach other, it is signaled that it is necessary to perform an additionalprocess for synchronization during presentation according to the GOPstructures. Of course, synchronization between the left and right imagesis basically realized by PTS. However, a necessary process may bepreviously performed through signaling of the receiving unit. As anexample, overall delay is adjusted to one having greater delay of theleft and right images.

If ES_level_composition_flag is 1, it means that ES-level multiplexingis used. If ES_level_composition_flag is 0, it means that TS-levelmultiplexing is used.

Hereinafter, an example in which PID is used will be described withreference to FIG. 5 b. However, only other syntaxes except the syntaxesdescribed with reference to FIG. 5 a will be described.

Primary_PID_flag is a flag present only in TS-level multiplexing. IFPrimary_PID_flag is 1, it means that a Primary_PID syntax is present.Otherwise, stereoscopic_stream_descriptor( ) is present to confirm PIDof the primary view.

Primary_PID specifies PID of the primary view to determine the primaryview from PID included in PMT.

Right_Is_Primary_flag is a flag present only in TS-level multiplexing.If Right_Is_Primary_flag is 1, it means that the primary view is a rightimage. Otherwise, it means that the primary view is a left image.

Information regarding the primary view and the left image is providedfrom service_compatible_stereoscopic_video_descriptor. Consequently,stereoscopic_stream_descriptor is not present and it is possible todistinguish the primary view and the left image using one descriptor.Left_PID may be informed and Right_Is_Primary_flag may be designatedusing a similar method, which do not deviate from the gist of thepresent invention.

In a case in which Primary_PID and Right_Is_Primary_flag are used,stereoscopic_stream_descriptor is present to distinguish the primaryview and the right image.

FIG. 6 show stereoscopic_stream_descriptor according to an embodiment ofthe present invention. As previously described,stereoscopic_stream_descriptor is a descriptor related to individual ESsof left and right images and serves to specify whether the current ES isa primary view in a stereoscopic image.

In a TS-level composition mode, each ES is described. In an ES-levelcomposition mode, one ES is described. Consequently, this descriptorconsiders both the two modes.

If Primary_flag is set to 1, it means that the current ES is a primaryview. In this case, the primary view must be reproduced.

If Left_flag is set to 1, it means that the current ES is a bitstream ofthe left image.

If Frist_Primary_flag is set to 1, in a case in which two imagebitstreams of ES-level are assembled (interleaved) in arbitrary steps,it is signaled that the first part is a bitstream corresponding to theprimary view.

If First_Left_flag is set to 1, in a case in which two image bitstreamsof ES-level are assembled (interleaved) in arbitrary steps, it issignaled that the first part is a bitstream corresponding to the leftimage.

Instead of describing the primary view or the left image, the secondaryview of the right image may be described as needed, which do not deviatefrom the gist of the present invention.

MPEG2_video_(—)3d_frame_frame_packing_arrangement_descriptor is shown inFIG. 7.

MPEG2_video_(—)3d_frame_frame_packing_arrangement_descriptor( ) definedin the frame-compatible mode is used as information related to Framepacking arrangement. Semantics may also be identical to those defined inthe frame-compatible mode.

FIG. 8 is a flowchart showing a multiplexing process in theservice-compatible mode according to the embodiment of the presentinvention. Hereinafter, a multiplexing process in the service-compatiblemode according to the embodiment of the present invention will bedescribed with reference to FIG. 8.

At S800, a PMT length is confirmed using section_length.

At S802, a syntax including program_number is read.

At S804, a descriptor length is confirmed using program_info_length.

At S806, it is confirmed whether all descriptors related to program infohave been read. If all descriptors have been read, the procedure movesto S820 through A described in FIG. 8. If all descriptors have not beenread, the procedure moves to S808, where one descriptor related toprogram info is read.

At S810, it is confirmed whether the read descriptor isservice_compatible_stereoscopic_video_decriptor. If the read descriptoris service_compatible_stereoscopic_video_decriptor, the procedure movesto S812. If the read descriptor is notservice_compatible_stereoscopic_video_decriptor, the procedure moves toS806.

At S812, a syntax including ES_level_composition_flag is read to analyzesynthesis information related to left and right images.

At S814, it is confirmed whether ES_level_compatible_flag has been set.If ES_level_compatible_flag has been set, the procedure moves to S816.If ES_level_compatible_flag has not been set, the procedure moves toS818.

At S816, an ES-level multiplexing structure mode is activated. At S818,a TS-level multiplexing structure mode is activated.

At S820, it is confirmed whether the PMT has been completely read. Ifthe PMT has been completely read, the procedure moves to S842. If thePMT has not been completely read, the procedure moves to S822. At S822,stream_type and elementary_PID are read.

At S824, a descriptor length is confirmed using ES_info_length.

At S826, it is confirmed whether all descriptors related to ES info havebeen read. If all descriptors have been read, the procedure moves toS820. If all descriptors have not been read, the procedure moves toS828.

At S828, one descriptor related to ES info is read and the proceduremoves to S830.

At S830, it is confirmed whether the read descriptor isstereoscopic_stream_descriptor. If the read descriptor isstereoscopic_stream_descriptor, the procedure moves to S834. If the readdescriptor is not stereoscopic_stream_descriptor, the procedure moves toS838.

At S834, Primary_flag and Left_flag are read. At S836, it is determinedwhether video data corresponding to the current element_PID are aprimary view and a left image.

At S838, First_Primary_flag and First_Left_flag are read. At S842, it isdetermined whether leading video data of data corresponding to thecurrent element_PID are a primary view and a left image.

At S842, CRC_(—)32 is read and a data error is verified.

FIG. 9 is a flowchart showing a process of de-assembling ES-levelmultiplexed bitstreams. Hereinafter, a process of de-assembling ES-levelmultiplexed bitstreams in a service-compatible mode according to anembodiment of the present invention will be described with reference toFIG. 9. The following process is performed on the assumption thatbitstreams are mixed in order of left to right. Those skilled in the artwill appreciate that bitstreams may be mixed in order of right to left.

At S900, PMT is parsed.

At S901, service_compatible_stereoscopic_video_descriptor( ) in PMT isparsed.

At S902, ES_level_composition_flag is confirmed to determine ES-levelmultiplexing.

At S903, MVC_bitstream_assembling_flag is confirmed to determine whetherassembling of bitstreams in ES-level multiplexing conforms MVC bitstreamassembling (defined in stereo_high_profile or multiview_high_profile).

At S904, stereosopic_stream_descriptor( ) in PMT is parsed.

At S905, First_Primary_flag is confirmed.

At S906, First_Left_flag is confirmed.

At S907, one AU is detected from received mixed bitstreams.

At S908, it is determined whether leading data are a left image fromFirst_Left_flag confirmed at S906.

At S909, it is determined whether the AU detected at S907 isodd-numbered AU. If the AU detected at S907 is odd-numbered AU, theprocedure moves to S910. If the AU detected at S907 is even-numbered AU,the procedure moves to S911.

At S910 and S911, the corresponding AU is de-assembled into left imageor right image bitstreams using the information determined at S909.

At S912, it is determined whether all AUs have been read. If all AUshave been read, the procedure moves to S913. If all AUs have not beenread, the procedure moves to S907.

At S913, it is determined whether leading data are a left image fromFirst_Primary_flag confirmed at S906. If First_Primary_flag is 1, theprocedure moves to S914. If First_Primary_flag is 0, the procedure movesto S915.

At S914 and S915, it is determined which of the bitstreams is a primaryview using the Primary information determined at S913.

At S916, the de-assembled bitstreams are transmitted to a decoder.

FIG. 10 is a view showing a bitstream de-assembling method according toMVC Bitstream Extraction corresponding to S907 to S912. When mixed leftand right bitstreams are received, it can be seen that the bitstreamsare assembled in AU steps and the first AU is a primary view or a leftimage through the process shown in FIG. 9. Consequently, the bitstreamsof the left and right images may be de-assembled as shown in FIG. 10although NAL Header is not parsed to confirm view_id and anchor_pic_flagpresent in the NAL Header.

Although the present invention has been described with reference to theembodiments shown in the drawings, the embodiments are illustrative.Therefore, those skilled in the art will appreciate that various andequivalent modifications may be embodied from the above embodiments.

Although the above description is focused on a 3D stereoscopicbroadcast, which is being currently tested and broadcast standards ofwhich are under establishment, broadcasting in the frame-compatible modeand in the service-compatible mode may be performed in other compositebroadcasts, such as a UHD TV broadcast and a multi-view broadcast.Consequently, the present invention is applicable to other compositebroadcasts, such as a UHD TV broadcast and a multi-view broadcast, aswell as a 3D stereoscopic broadcast.

The invention claimed is:
 1. A method of processing a stereoscopicthree-dimensional (3D) service in a digital broadcast receiver, themethod comprising: receiving a broadcast signal comprising a transportstream (TS), wherein the TS includes a Program Association Table (PAT);parsing the PAT, which has a specific packet identifier (PID), from thereceived TS; acquiring a Program Map Table (PMT) based on a PMT_PIDincluded in the parsed PAT; and processing the acquired PMT comprisingboth of at least two fields and at least two descriptors, wherein afirst field among the at least two fields indicates a PID of the TS, anda second field among the at least two fields identifies a stream type ofthe TS, wherein a first descriptor among the at least two descriptorsspecifies a type of service that is provided, the service typecorresponding to a two-dimensional (2D) service, a frame-compatiblestereoscopic 3D service or a service-compatible stereoscopic 3D service,wherein a second descriptor among the at least two descriptors providesinformation related to the service-compatible stereoscopic 3D servicethat carries left and right views in separate video streams, the seconddescriptor further comprising: first data indicating that a video streamincluded in the TS is a base video stream or an additional view videostream: second data indicating that the video stream is a left viewvideo stream or a right view video stream, and third data including anupsampling factor, required after the video stream is decoded, thatidentifies whether a coded resolution of the additional view videostream is the same as a coded resolution of the base video stream ordifferent from the coded resolution of the base video stream.
 2. Themethod of claim 1, wherein the up sampling factor further identifieswhether the coded resolution of the additional view video stream is a ½,⅔, or ¾ coded resolution of the base video stream.
 3. The method ofclaim 2, wherein the second descriptor further comprises fourth dataindicating that the additional view video stream is able to be used forthe 2D video service.
 4. The method of claim 3, wherein the first fieldcorresponds to an elementary PID of the PMT and the second fieldcorresponds to a stream type of the PMT.
 5. The method of claim 4,wherein a location of the first descriptor within the PMT is differentfrom a location of the second descriptor within the PMT.
 6. The methodof claim 5, further comprising: receiving a PMT having the firstdescriptor or multiple descriptors, wherein the multiple descriptorshave the first descriptor and either the second descriptor providinginformation related to the service-compatible stereoscopic 3D service ora third descriptor providing information related to the frame-compatiblestereoscopic 3D services; and processing the PMT having the firstdescriptor or multiple descriptors, wherein the third descriptor islocated in a loop following ES_info_length field in the PMT.